Whit by Iain Banks meets The Magus by John Fowles in this surreal, supernatural thriller by a Costa-shortlisted author. When her twin brother goes missing in Northern California, Vivian Owens follows his trail to the town of Mount Wookey, home to the followers of Telos: a mountain-worshipping cult that offers spiritual fulfilment to those who seek it. While trying to navigate the town's bizarre inhabitants and the seductive preaching of the initiates of Telos, Vivian will have to confront questions about herself, her family, and everything she thinks she knows about the world. She quickly realises that her search is about far more than her missing brother - it is a quest for the secret of happiness itself. To that end, there is only one question she needs to answer: what is really at the top of Mount Wookey?